1. Field of the Invention
The present invention concerns a lighting or signaling module, in particular for motor vehicles, which has an improved three-dimensional appearance when it is lit.
The invention is especially suitable for use in the domain of motor vehicles, such as for example, motorized two-wheelers, private cars, light utility vehicles or heavy goods vehicles.
2. Description of the Related Art
The document FR 2 627 256 discloses a signal light consisting essentially of a lamp fitted with a filament, a rear reflector and a transparent deflection element placed forward of the lamp. The rear reflector, in co-operation with the real light source, is designed to create, on a line essentially horizontal and perpendicular to the general direction of emission or optical axis x-x, a plurality of light sources, referred to in this document as virtual, distributed equidistantly on this line. To this effect, the rear reflector is subdivided into a plurality of segments which exhibit the shape of ellipsoids, the first focal point of which is situated on the filament and the second focal point of which is situated at the location of the virtual sources. The transparent deflection element arranged forward of the sources has an essentially constant vertical section, with which a focal point is associated, and designed to deflect rays of light projected from focal point vertically so that they propagate essentially in parallel with a horizontal plane, this element being obtained by a displacement of section such that the focal point essentially follows the line of sources.
An arrangement of this type is intended to produce a signal light of great width in relation to its height, such as for example a third brake light in raised central position. The function of the deflector element arranged forward of the light sources is to act on the angle of site of the rays diverging from the light sources, to return it to a value close to zero, while leaving their azimuth angle practically unchanged.
Moreover, the reflector is designed so that each virtual source emits light rays forwards essentially in the same angular range, in a horizontal median plane, so that all of the illuminating area of the lamp retains a homogeneous appearance from wherever it is observed in this angular range.
The result of this is that the light known from this document presents a homogenous illuminated area, in which the light sources can no longer be distinguished, and with which it is impossible to obtain special aesthetic effects.
There is also known, from the document EP 0 678 703, a vehicle light which comprises a light source cooperating with a reflector, the light being designed to give the effect of a multitude of punctiform, or practically punctiform, light sources. According to this document, the reflector comprises a plurality of lenticular reflective elements, each provided with a convex or concave reflective surface, distributed in a fundamentally uniform way over the surface of the reflector. The reflective elements are arranged in lines, horizontally and vertically parallel, or radial in relation to the longitudinal axis of the light, or they occupy predetermined circular sectors on circumferences or segments of circumferences which are concentric in relation to the lamp.
The reflective elements described by this document have curved, convex or concave surfaces, whose radii of curvature in horizontal and vertical direction are selected independently of each other depending on the light effect desired. The reflective elements are thus visible through a smooth closure glass as a connected plurality of light images.
An embodiment of this type allows very little leeway for the design of the reflective elements, so that no special aesthetic or style effects can be achieved. This document, in fact, makes provision only for matricial or circular configurations for the reflective elements. Moreover, the reflective elements constituting the plurality of images obtained remain localized at the reflector, so that an observer situated outside the axis of emission of the signaling beam sees only part of the plurality of images. Moreover, in order to satisfy the photometric grids demanded by legislation, the rows of reflective elements constituting the reflector have to be oriented in predetermined directions, which creates zones of shadow in a frontal view of the light.
Also known, from U.S. Pat. No. 6,244,731, is a lighting or signaling device composed of a light source, a composite reflector, consisting of a plurality of reflecting surface units and of aspheric lenses corresponding to each of the reflective surface units, and intended to emit a light beam along an optical axis.
The plurality of reflecting surface units is divided into several groups. Each reflecting surface unit is an ellipsoid segment, one focal point of which is centered on the light source, and the second focal point of which is situated on a line passing through the first focal point and inclined on the optical axis. The reflecting surface units of one group are distributed concentrically around the optical axis, so as not to overlap.
The aspherical lenses are convergent, and they are each focused on a second focal point of a reflecting surface element so as to emit parallel light beams in the direction of the optical axis.
The aims of a design of this type are to obtain a new style of lighting or signaling device, with a plurality of lenses visible from the outside of this device, to control the distribution of light inside the light beam resulting from the superimposition of the elementary light beams, and to select the visible illuminated surface of the device. In fact, only the external faces of the aspheric lenses are visible.